src: enhance C++ sprintf utility

himself65 · targos · commit 4b5fd248559e · 2020-04-22T18:24:54.000+02:00
PR-URL: #32385 Reviewed-By: Anna Henningsen <anna@addaleax.net> Reviewed-By: James M Snell <jasnell@gmail.com> Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com>
diff --git a/src/debug_utils-inl.h b/src/debug_utils-inl.h
@@ -27,13 +27,39 @@ struct ToStringHelper {
   }
   static std::string Convert(const std::string& value) { return value; }
   static std::string Convert(bool value) { return value ? "true" : "false"; }
+  template <unsigned BASE_BITS,
+            typename T,
+            typename std::enable_if<std::is_integral<T>::value, int>::type = 0>
+  static std::string BaseConvert(T value) {
+    char ret[3 * sizeof(T)];
+    char* ptr = ret + 3 * sizeof(T) - 1;
+    *ptr = '\0';
+    const char* digits = "0123456789abcdef";
+    do {
+      unsigned digit = value & ((1 << BASE_BITS) - 1);
+      *--ptr =
+          (BASE_BITS < 4 ? static_cast<char>('0' + digit) : digits[digit]);
+    } while ((value >>= BASE_BITS) != 0);
+    return ptr;
+  }
+  template <unsigned BASE_BITS,
+            typename T,
+            typename std::enable_if<!std::is_integral<T>::value, int>::type = 0>
+  static std::string BaseConvert(T value) {
+    return Convert(std::forward<T>(value));
+  }
 };
 
 template <typename T>
 std::string ToString(const T& value) {
   return ToStringHelper::Convert(value);
 }
 
+template <unsigned BASE_BITS, typename T>
+std::string ToBaseString(T&& value) {
+  return ToStringHelper::BaseConvert<BASE_BITS>(std::forward<T>(value));
+}
+
 inline std::string SPrintFImpl(const char* format) {
   const char* p = strchr(format, '%');
   if (LIKELY(p == nullptr)) return format;
@@ -64,7 +90,18 @@ std::string COLD_NOINLINE SPrintFImpl(  // NOLINT(runtime/string)
     case 'd':
     case 'i':
     case 'u':
-    case 's': ret += ToString(arg); break;
+    case 's':
+      ret += ToString(arg);
+      break;
+    case 'o':
+      ret += ToBaseString<3>(arg);
+      break;
+    case 'x':
+      ret += ToBaseString<4>(arg);
+      break;
+    case 'X':
+      ret += node::ToUpper(ToBaseString<4>(arg));
+      break;
     case 'p': {
       CHECK(std::is_pointer<typename std::remove_reference<Arg>::type>::value);
       char out[20];
diff --git a/src/debug_utils.h b/src/debug_utils.h
@@ -5,6 +5,7 @@
 
 #include "async_wrap.h"
 
+#include <algorithm>
 #include <sstream>
 #include <string>
 
diff --git a/test/cctest/test_util.cc b/test/cctest/test_util.cc
@@ -268,6 +268,12 @@ TEST(UtilTest, SPrintF) {
   EXPECT_EQ(SPrintF("%u", -10000000000LL), "-10000000000");
   EXPECT_EQ(SPrintF("%i", 10), "10");
   EXPECT_EQ(SPrintF("%d", 10), "10");
+  EXPECT_EQ(SPrintF("%x", 15), "f");
+  EXPECT_EQ(SPrintF("%x", 16), "10");
+  EXPECT_EQ(SPrintF("%X", 15), "F");
+  EXPECT_EQ(SPrintF("%X", 16), "10");
+  EXPECT_EQ(SPrintF("%o", 7), "7");
+  EXPECT_EQ(SPrintF("%o", 8), "10");
 
   EXPECT_EQ(atof(SPrintF("%s", 0.5).c_str()), 0.5);
   EXPECT_EQ(atof(SPrintF("%s", -0.5).c_str()), -0.5);
